Field of the Invention
The present invention relates to an image pickup apparatus and a method for controlling the image pickup apparatus.
Description of the Related Art
In recent years, an image pickup apparatus using an image pickup element such as a CMOS sensor has become multifunctional. Not only generation of acquired images such as still and moving images, but also control of the image pickup apparatus such as focusing has been carried out based on object information obtained by the image pickup element.
For example, in Japanese Patent Application Laid-Open No. 2001-124984, there is disclosed such a technology that signals obtained from the image pickup element are used to enable focus detection in a pupil division system. In Japanese Patent Application Laid-Open No. 2001-124984, each pixel of the image pickup element includes one microlens and two photodiodes so that the photodiodes respectively receive light passing through different pupils of an image pickup lens. Output signals from those two photodiodes are compared with each other to enable focus detection, and the output signals from those two photodiodes are added to each other to enable generation of an acquired image.